The present invention relates to an electronic built-in device with a front wall and a built-in housing part comprising a cover, a base, side walls and a rear wall, and also with a printed circuit board, arranged transversely in relation to the rear wall, connected to at least two housing elements of the built-in housing part and carrying the electronic subassemblies and components of the built-in device and also a plug socket, the access to the contacts of the plug socket aligned parallel to the printed circuit board taking place through a clearance provided on the rear wall of the built-in housing part.
Walls of built in devices are generally constructed of rather thin steel sheets so as to maximize available space within the device. Accordingly, the built-in housing part or housing forms an enclosure which serves to protect its interior from dust and unwanted contact. In addition, the housing serves as an electromagnetic shield for electronic components within the housing. Such components may include a printed circuit board, which may further cooperate with a structural part within the housing so as to serve as part of a reinforcing skeleton.
Components within the housing are typically subject to mechanical forces resulting from connection and disconnection with data and/or power sources. This normally occurs via acts of plugging and unplugging lines. Per this action, the components, such as the printed circuit board is susceptible to structural damage and/or bending. Accordingly, circuit board components and connections become vulnerable to damage, and, the wear and tear tends to shorten lifespans of such vulnerable components. Because of the relatively large production tolerances for injection-molded parts, this applies even if the plug socket which is produced in this way is fastened to the printed circuit board by aligning pins and locking hooks.
If, in the case of the present built-in device, such as may be the case for a tachograph wherein a plug socket provided with a plurality of plug chambers formed next to one another, torsional moments not only occur transversely, but also parallel to the plane of the printed circuit board during the inserting and pulling of the usual eight-pin plugs. Moreover, during the installation of a tachograph in a commercial vehicle, considerable forces can occur in all manner of different directions at the installation location, (i.e. in the region within reach of the driver), on account of the spatially unfavorable installation conditions which, under some circumstances, make it necessary for the plugs to be blind fitted. Furthermore, in the case of a tachograph, after its installation, the cluster of lines, of considerable rigidity, may exert a constant elastic reaction on the plug socket on account of the deflections required during installation and possibly also compression.